1. Field of the Invention
The present invention relates to a catheter introduction set which provides reliable and safe introduction of catheters into blood vessels.
2. Description of the Prior Art
U.S. Pat. No. 4,417,886 discloses a catheter introduction set comprising a kit with a small, flexible wire guide on the interior of the introduction needle. The wire is used for guiding a catheter surrounding the introduction needle in place as the introduction needle is withdrawn from the blood vessel. The guide wire is solid and has to be withdrawn completely from the needle interior when the needle is first introduced into a vessel to permit blood to surge back into a sight chamber or into a tube that is attached to the introduction set. After the feedback of blood the wire is then moved through the needle into the lumen of the blood vessel. The catheter is slid along the guide into the vessel and the needle is withdrawn while leaving the catheter tube in place in the blood vessel. The guide wire also has to be long enough to be withdrawn from the needle and then rethreaded through the needle after the needle has been introduced into the blood vessel. An extra long guide tube is necessary for preventing contamination of the guide wire as the wire is withdrawn during the initial introduction of the needle to permit blood to flow out of the needle for an indication that a blood vessel has been pierced. This elongates a system substantially and causes extra cost in making and packaging, and also increases the difficulty of use.
U.S. Pat. No. 4,068,660 also shows a catheter placement assembly improvement utilizing a hollow spring on the interior of a catheter tube or plastic cannula, which catheter in turn is on the interior of the needle used for insertion into a blood vessel. This arrangement requires a needle that is larger diameter than the catheter end, and is otherwise somewhat similar to the unit shown in U.S. Pat. No. 4,417,886.
U.S. Pat. No. 3,903,885 also shows a device for introducing flexible catheters having a center stiffening mandrel 13 that is placed on the interior of the catheter.
U.S. Pat. No. 4,068,659 shows a catheter placement assembly which also uses an interior plastic cannula that is on the inside of the needle, and which is slid through the needle into a blood vessel once the needle has penetrated the wall of the blood vessel. Here, too, a large size needle is necessary in order to have a full size catheter, and it is necessary that the assembly be elongated to accommodate the need for maintaining the exposed portions sterile.
U.S. Pat. No. 3,262,448 shows an intervenious catheter placement set with a catheter positioned on the interior of a needle.
U.S. Pat. No. 4,037,660 also illustrates a catheter set with a catheter introduced into the side of the needle and adapted to be threaded into the blood vessel after the needle has been placed therein.
Various devices have been also made for holding catheters and the associated tubing in place. U.S. Pat. No. 4,324,237 shows such a device having a complex securement and dressing device providing a window over the puncture or wound site.